It's view ports, as pointed out previously, are incredibly slow.
Open your settings. Set the rendering method to a different DLL. Problem solved.
Navigation in them is horrible (when compared to other editors or to 3D applications).
Change your key bindings! I set mine up to be a standard WASD control scheme. You should do the same.
Snapping (which is fairly essential) is terrible (as you pointed out).
You're right, snapping really is a problem. I find myself constantly repositioning unruly vertices and edges all the time. That's the only thing that really bothers me about WED, though.
The visual quality of the view ports is equally poor.
You can see well enough to do what you need to do, though. This isn't really much of a problem.
You cannot easily manipulate items in the left-side list (only one item there can be selected at a time, moved at a time, etc).
Now that's a real problem that I never thought about. Still, I've never had to use that list, so it doesn't bother me too much.